大海为什么是蓝色的？

The ocean is blue because water absorbs colors in the red part of the light spectrum. Like a filter, it leaves behind the colors in the blue part of the spectrum for us to see. The ocean can also look green, red or other colors when light bounces off sediment and tiny particles floating in the water. Most of the ocean, however, is completely dark. Very little light reaches deeper than about 200 meters (656 feet), and no light at all reaches deeper than 1,000 meters (3,280 feet).

大海之所以是蓝色的，是因为水会吸收光谱中偏红的颜色。水就像一个滤镜，把光谱中偏蓝的颜色留下来，让我们看见。当光线照到水中漂浮的泥沙和微小颗粒并反射回来时，海水也可能呈现绿色、红色或其他颜色。不过，海洋的绝大部分其实是一片漆黑。能照到约 200 米（656 英尺）以下的光非常少，而到了 1000 米（3280 英尺）以下，就完全没有光了。